Configuring the Speech Server engine
This topic organizes parameters by activity. For an alphabetical list, see the Speech Server parameter reference.
System administrators might set these parameters during Speech Server installation, or later when provisioning applications:
Parameter |
Description |
Value |
---|---|---|
Specifies how the server behaves during shutdown. |
Boolean 0 means immediate shutdown. 1 means graceful shutdown—the server rejects new connections and waits until active connections end. DEFAULT: 0 |
|
Specifies the maximum number of concurrently active SIP server sessions. |
Integer: 1–10,000. DEFAULT: 96 |
|
Specifies the initial number of worker threads started by the server. |
Integer DEFAULT: 1 |
|
Specifies the maximum number of worker threads in the server. |
Integer: 1–INT_MAX threads. Typically, the number must be equal to the planned number of concurrently served sessions. DEFAULT: 250 |
The following parameters control protocols voice browsers use to communicate during a Speech Server session. These parameters are optional: you typically use them to integrate Nuance products with an existing system. You can set values for several types of protocol:
- Network transport layer: TCP, UDP
- Session control: SIP (RTSP for MRCPv1)
- Messaging: MRCPv1 or MRCPv2
- Audio: RTP
- MRCPv2 security: TLS (messaging), SRTP (audio). For TLS parameters, see Configuring network security.
Parameter |
Description |
Value |
---|---|---|
Specifies the maximum number of concurrently active server sessions. |
Integer: 1–10,000. DEFAULT: 500 |
|
Specifies the session timeout for RTSP transport. |
Integer: Maximum time (in milliseconds) to wait for the next message in a session. DEFAULT: 60000 (1 minute) |
|
Specifies the session RTSP port to use for the server. |
Integer. An available port number. DEFAULT: 4900 |
|
Specifies the maximum number of seconds to wait for activity before closing the TCP connection, after the session was deleted on session timeout. |
Integer: seconds. Minimum 1s 0; there is no maximum. DEFAULT: 180 |
|
Specifies the logging level of the SIP stack. |
Integer: -1 to 8 (9 and 666 for Nuance internal use) DEFAULT: -1 (no SIP logging) |
|
Specifies the maximum number of concurrently active SIP server sessions. |
Integer: 1–10,000. DEFAULT: 96 |
|
Specifies the maximum time to wait for the next message in a session. |
Integer: 0–INT_MAX (milliseconds) DEFAULT: 60000 (1 minute) |
|
Specifies the SIP TCP port to use for the Speech Server. |
An available port number DEFAULT: 5060 |
|
Specifies the SIP UDP port to use for the Speech Server. |
An available port number DEFAULT: 5060 |
|
Specifies the MRCP2 port to use for the server. |
An available port number DEFAULT: 6075 |
|
Specifies the maximum timeout before receiving the next data from a TCP (TLS) socket. |
Integer: seconds. Minimum is 0; there is no maximum. DEFAULT: 20 (seconds) |
|
Specifies the audio buffer size for RTP audio reception. |
Integer: 1000–INT_MAX (milliseconds) DEFAULT: 5000 |
|
Specifies the maximum number of concurrently active RTP server sessions. |
Integer: 1–<maxsessions>, where maxsessions is the maximum of the following three parameters:
DEFAULT: 600 |
|
Specifies the maximum size of accepted RTP packets. |
Bytes. Minimum is 0; there is no maximum. DEFAULT: 1024 |
|
Specifies the starting port for RTP communication. |
An available port number DEFAULT: 7892 |
|
Specifies whether the server accepts packets from ports other than the UDP port and IP address. |
Boolean 1 (default): rejects packets from any other port. 0: the server does not check the UDP port, and accepts packets from any port. DEFAULT: 1 |
In order to improve performance, you may choose to split RTP and SIP traffic such that they are handled on a separate network interface cards (NICs).
Nuance Speech Server can specify values for the Differentiated Services (DSCP) field in the IP header to correspond with the values expected by the gateway.
DSCP (Differentiated Services Code Point) replaces TOS (type of service) and other QoS (quality of service) mechanisms. DSCP is a group of six bits that announce the quality of service desired for IP packets. Higher values represent higher IP priority.
Set this field independently for MRCP, SIP, and RTP using the following parameters:
Protocol |
Parameter |
Value |
---|---|---|
MRCP |
Integer: decimal DSCP value representing the quality of service desired. DEFAULT: 96 (CS3) |
|
SIP |
Integer: decimal DSCP value representing the quality of service desired. DEFAULT: 96 (CS3) |
|
RTP |
Integer: decimal DSCP value representing the quality of service desired. DEFAULT: 184 (EF) |
Note: Controlling DSCP is supported only for Linux systems.
Nuance Speech Server includes a tone detector module that can identify specific in-band telephony tone signals which go undetected by most gateways.
Use these parameters to control the tone detector.
Parameter |
Description |
Value |
---|---|---|
Enables tone detection and points to the configuration file that Speech Server uses to configure the tone detection library. |
Path. For example: $NSSSVRSDK/config/tonedef-en-us.xml. DEFAULT: $NSSSVRSDK/config/tones.all.on The parameter has no default value, but the NSS baseline configuration file sets a value at installation. |
|
Specifies the software that uses the tone detection library. The <originator> component of the event name. A typical value for this parameter is "nss". |
String. For example: server.toneDetector.originator VXIString nss DEFAULT: nss |
|
Specifies the interval after which the tone detector stops operating. |
Integer. 0–INT_MAX (milliseconds) DEFAULT: 20000 |
See also Detecting telephony tones.
Use this parameter to connect one Speech Server to one recognition server. Do not use this parameter to connect one Speech Server to more than one recognition server.
Parameter |
Description |
Value |
---|---|---|
Specifies the address of a single Nuance recognition server. |
Server address of the form host:port DEFAULT: localhost:8200 |
For low-level recognition parameters, see Configuring recognition resources.
Use this parameter connect one Speech Server to one Vocalizer host/instance. Do not use this parameter to cocnnect one Speech Server to more than one Vocalizer host/instance.
Parameter |
Description |
Value |
---|---|---|
Specifies the address of a single NuanceVocalizer host. |
Host address of the form host:port DEFAULT: localhost:9200 |
For low-level recognition parameters, see Configuring text-to-speech resources.
Use this parameter to connect Speech Server to one Natural Language Processing service host/instance:
Parameter |
Description |
Value |
---|---|---|
Specifies the address of a single Natural Language Processing service host or instance. |
Location (WebSocket URI) of the Natural Language Processing service. DEFAULT: wss://localhost:8443/nlps |
Use these parameters to control whether Krypton is available for raw recognition (Krypton-only) or semantic interpretation:
Parameter |
Description |
Value |
---|---|---|
Enables Dragon Voice for Krypton-only recognition (raw recognition with no semantic interpretation). |
True or False DEFAULT: False (disabled) |
|
server.nlps.audioOnly |
Enables Dragon Voice for Krypton-only recognition (raw recognition with no semantic interpretation). |
Boolean DEFAULT: 0 (disabled) |
Speech Server can record a complete conversation, that is, a realtime mixed capture of both the inbound and outbound audio streams of a call (a particular RTSP [MRCPv1] or SIP [MRCPv2] session) exactly as they occurred.
Use these parameters to control whole call recording:
Parameter |
Description |
Value |
---|---|---|
Enables whole call recording. |
Boolean DEFAULT: 0 (disabled) |
|
Specifies the maximum duration of whole call recording. Whole call recording must be enabled first by setting server.rtp.wcr.enable to 1. |
Integer: minutes. Minimum is 0; there is no maximum. DEFAULT: 60 (highest recommended value) |
|
Specifies whether the whole call recording is saved as a single file or split into separate files, with each file containing audio from a different party. Whole call recording must be enabled first by setting server.rtp.wcr.enable to 1. |
Integer:
DEFAULT: 0 |
|
Specifies the percentage of calls that are randomly selected for recording. Whole call recording must be enabled first by setting server.rtp.wcr.enable to 1. |
Integer: 0–100. DEFAULT: 1 (percent) |
Use these parameters to control behaviors when applications fetch and cache grammars and audio files:
Parameter |
Description |
Value |
---|---|---|
Maps file extension to a MIME type. |
MIME type that corresponds to the extension in the parameter name. DEFAULT: (none) |
|
Specifies the user agent name presented to the web server when HTTP requests are made. |
String DEFAULT: NSS-MRCP/6.1 |
|
Specifies the default timeout for downloading a URI (from open through the final byte). |
Integer: 1–INT_MAX (milliseconds) DEFAULT: 30000 (30 seconds) |
|
Specifies the default timeout for reading or writing a block of data over a web server connection. |
Integer: 1–INT_MAX (milliseconds) DEFAULT: 30000 |
|
Specifies the default timeout for opening a connection to a web server. |
Integer: 1–INT_MAX (milliseconds) DEFAULT: 30000 |
Optional. Use these parameters to define rules for fetching documents through a proxy server. The advantage of these parameters is that they apply to fetches by Speech Server, Recognizer, and Vocalizer instead of configuring proxies for each individual engine.
Parameter |
Description |
Value |
---|---|---|
server.inet.HTTPproxyRules |
Rules for using proxy servers to fetch documents from application servers using HTTP. |
DEFAULT: (none) |
server.inet.HTTPSproxyRules |
Rules for using proxy servers to fetch documents from application servers using HTTPS. |
DEFAULT: (none) |
Alternatively, you can use these parameters to set up a proxy server for Speech Server fetches:
Parameter |
Description |
Value |
---|---|---|
Specifies the list of servers to be accessed directly, rather than through a proxy server. |
List of host names separated by commas. DEFAULT: (none) |
|
Specifies a port for the HTTP proxy server. |
Integer. An available port number. DEFAULT: 1111 |
|
An HTTP proxy server host used by Speech Server when fetching audio files from an application server. |
Host name or IP address of the proxy server host. DEFAULT: myHost |
Use these parameters to control call logging:
Parameter |
Description |
Value |
---|---|---|
Enables call logging. When disabled, no call logs are written. |
Boolean DEFAULT: 1 (enabled) |
|
Parent directory where the system writes call logs. Deprecated. Use swirec.secure_context or switts.secure_context instead. |
DEFAULT: $NUANCE_DATA_DIR |
|
Specifies the listening TCP port assigned to the call log server. |
TCP port number DEFAULT: 10101 |
|
server.callLog.baseDirectory |
Specifies the parent directory where the system writes call logs. |
Directory path. The directory does not need to exist in advance. DEFAULT: $NUANCE_DATA_DIR/callLogs or $NUANCE_DATA_DIR/CompanyName/callLogs/ApplicationName/yyyy/mmMonth/dd/hh |
Specify cleanup behavior when the log directory fills:
Parameter |
Description |
Value |
---|---|---|
Enables removal of old log files (audio and text). |
Boolean DEFAULT: 1 (enabled) |
|
Specifies time for the call log server cleanup process to pause between cleaning cycles. |
Amount of time (minutes) that the call log cleanup process pauses between cleaning cycles. Maximum pause is 10080 (7 days). DEFAULT: 1 (minute) |
|
Controls how long to keep each type of log file before deletion. |
A string of fields (separated by semi-colons) where each field indicates a category or type of log file followed by a colon and a time designation (the rate). Set individually for each file type. DEFAULT: Depends on file type. |
|
Specifies the minimum available disk space for writing call logs. |
Integer in MB: 10 to MAXINT on your system. The minimum value is 10 MB. There is no upper limit. When the available space falls below this amount, logging is disable for the session until space is freed. The space is checked approximately every 20 minutes. DEFAULT: 1073 MB |
|
Threshold to warn operators that the available disk space for call logging is too low. |
Integer (megabytes): 10 to the value of MAXINT on your system. There is no upper limit. DEFAULT: 2146 (2 gigabytes) |
Enable TLS log security:
Parameter |
Description |
Value |
---|---|---|
Specifies the listening TLS port for clients to communicate with call log server. |
Integer. An available port number for TLS. DEFAULT: 10102 |
Limit the number of audio recordings saved, in order to conserve disk storage space:
Parameter |
Description |
Value |
---|---|---|
Specifies the percentage of randomly-selected utterances saved as audio files. |
Integer: 0–100. DEFAULT: 100 |
Enable diagnostic logging:
Parameter |
Description |
Value |
---|---|---|
Controls the logged output by enabling tags in diagnostic log files. |
Integers representing one or more tags in the TRC tagmap files. DEFAULT: (none) |
Specify the location of diagnostic logs:
Parameter |
Description |
Value |
---|---|---|
Specifies the base directory for diagnostic logging in per-company mode. |
Directory path name DEFAULT: $NUANCE_DATA_DIR/system/diagnosticLogs |
|
Specifies the location for Speech Server and Vocalizer diagnostic files. |
String DEFAULT: $NUANCE_DATA_DIR/system/diagnosticLogs/nss.log. |
Control diagnostic log size:
Parameter |
Description |
Value |
---|---|---|
Specifies the maximum size to allow for the MRCP message log directory. |
Integer: 0–2047 megabytes. DEFAULT: 50 (MB) |
|
Specifies the maximum size for Speech Server and Vocalizer diagnostic files. |
Integer: 0–2047 megabytes. DEFAULT: 50 (MB) |
Enable diagnostic log options:
Parameter |
Description |
Value |
---|---|---|
Keeps the log file open between writes for faster logging. |
Boolean DEFAULT: 1 |
|
Writes logs to standard out as well as to a file. |
Boolean DEFAULT: 1 (standard out as well as to a file) |
Control the contents of diagnostic logs:
Parameter |
Description |
Value |
---|---|---|
Specifies a particular aspect of a component to include in the Speech Server diagnostic log (nss.log) |
Boolean. 1 means to include diagnostic information for the module specified by the index xxxx. DEFAULT: 0 (tag not logged) |
|
Writes diagnostic information for different components to separate log files instead of the main diagnostic log. |
String. The value x specifies error maps for different components as follows: 0 $NSSSVRSDK/config/serverErrors.xml DEFAULT: (none) |
|
Enables additional logging: logs a diagnostic message on every enter and return from a function. |
Boolean DEFAULT:0 (no extra logging) |
|
Reports the error texts from error map files. |
Boolean DEFAULT: 1 (report error text) |
Protect confidential information in diagnostic logs:
Parameter |
Description |
Value |
---|---|---|
Writes diagnostic information to separate log files (per company) instead of the main diagnostic log. |
Boolean. 0 means a single diagnostic log covers all companies. DEFAULT: 0 (disabled, a single log is written) |
|
Specifies whether recognition messages from the browser appear in Speech Server diagnostic logs. |
Boolean DEFAULT: 0 (disabled, browser messages written) |
|
Specifies whether text-to-speech messages from the browser appear in Speech Server diagnostic logs. |
Boolean DEFAULT: 0 (disabled, browser messages written) |
|
Specifies whether confidential data is suppressed in Speech Server diagnostic logs. |
Boolean DEFAULT: 1 (enabled, secure data suppressed) |
|
Specifies whether Speech Server suppresses URI strings that contain confidential data. |
Boolean DEFAULT: 0 (disabled, URIs are written) |
Nuance Speech Suite can protect confidential data as it moves between processes and gets written to disk. This might include information such as names, addresses, telephone numbers, account numbers, and passwords. The data can be DTMF touchtone signals, spoken utterances, synthesized speech requests, recognized speech, and saved audio files.
Use these parameters to to suppress or encrypt confidential information:
Parameter |
Description |
Value |
---|---|---|
Specifies whether recognition messages from the browser appear in Speech Server diagnostic logs. |
Boolean DEFAULT: 0 (disabled, browser messages written) |
|
Specifies whether text-to-speech messages from the browser appear in Speech Server diagnostic logs. |
Boolean DEFAULT: 0 (disabled, browser messages written) |
|
Specifies whether confidential data is suppressed in Speech Server diagnostic logs. |
Boolean DEFAULT: 1 (enabled, secure data suppressed) |
|
Specifies whether Speech Server suppresses URI strings that contain confidential data. |
Boolean DEFAULT: 0 (disabled, URIs are written) |
|
Replaces confidential data in whole-call recordings with silence. |
Boolean DEFAULT: (none) |
|
Sets recognizer security levels for protecting confidential data, typically for a single event. |
open, encrypt, suppress DEFAULT: open (no security) |
|
Replaces confidential data in whole-call recordings with silence. |
Boolean DEFAULT: (none) |
|
Sets security levels for protecting confidential data in logs of text-to-speech conversions, typically for a single event. |
open, encrypt, suppress DEFAULT: open (no security) |